We find that if the person has folders from other people (such as calendars, Inbox folders, etc) shared to their email account so that they can access them, it increases the size of their Outlook cache file.

So one of my managers (running latest MAPI with Outlook 2013 on 64 bit Windows 7) had a 6GB dat file in his profile. It corrupted. I restored the dat file prior to the corruption and it is working fine again.
However, the dilemma is the cache file shouldn't be this big, theoretically. He had a large number of emails, which he has since archived off to multiple PST files. His account is reporting only about 100MB in size now.

If this was a PST file, I would run Outlook's compression on it. This does not seem to be possible. So how do we compress the cache file? I know I can delete the profile but I really don't want to go through that. Any ideas? If I simply delete the cache dat file, will it be recreated once Outlook is started, as opposed to deleting the whole profile and having to reconfigure the profile again?

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